Formaldehyde increases MAGIC gel dosimeter melting point and sensitivity

Area of Science:

• Medical Physics
• Radiotherapy
• Polymer Science

Background:

• Polymeric gel dosimeters are crucial for verifying 3D dose distributions in radiotherapy.
• Gel melting due to temperature variations limits their widespread application.
• Maintaining dosimeter integrity is essential for accurate treatment verification.

Purpose of the Study:

• To investigate the effect of formaldehyde on the thermal stability of polymeric gel dosimeters.
• To enhance the usability of gel dosimeters in environments with elevated temperatures.
• To assess the impact of formaldehyde on gel sensitivity and measurement uncertainty.

Main Methods:

• Preparation of MAGIC type gel dosimeters with varying concentrations of formaldehyde solution.
• Measurement of melting points of prepared gel samples.
• Evaluation of gel sensitivity and relaxation rate R2 uncertainty before and after formaldehyde addition.

Main Results:

• Addition of 3% formaldehyde solution increased the melting point of MAGIC gel from 25°C to 69°C.
• Gel sensitivity increased by 12.5% with formaldehyde addition.
• A significant decrease in relaxation rate R2 uncertainty was observed.

Conclusions:

• Formaldehyde addition effectively enhances the thermal stability of polymeric gel dosimeters.
• This modification allows for reliable radiotherapy dose verification at body temperature and in warmer environments.
• Formaldehyde improves dosimeter performance by increasing sensitivity and reducing measurement uncertainty.